The instant invention relates to a pellet implantation devices and tools including kits for implanting therapeutic pellets subcutaneously into a patient. The invention relates more specifically to mechanical devices designed for subcutaneous implantation of potentially fragile medicinal pellets, such as hormone pellets that act at a constant rate over a prolonged period of time used largely in treating mammalian subjects.
An implantation procedure is typically related to subcutaneously implanted hormone pellets but could be used in similar applications for other medicaments. The individual pellets are typically smaller than a grain of rice and are implanted into the subcutaneous tissue, where they provide a slow continuous release of hormone or other medicaments into the bloodstream. It is imperative that the implantation device does not damage the pellets as any such damage that changes the release rate could have serious consequences for a patient.
The pellets can be implanted in the lower abdomen or buttocks in a physician's office with the use of a local anesthetic and a small controlled incision for insertion. The release of the drug can continue over a 3-6-month period or longer.
The kit can include a pellet loading tool designed to easily load a hollow needle with pellets while maintaining sterility of both the pellets and the needle and protecting the user, a medical professional, from injury.
A sheathed scalpel included in the kit is used to make a tailored incision at a preselected area for insertion. After the needle is inserted through the incision and into the patient, the operator presses a tab causing the needle to retract thus carefully deploying the pellets in a linear single file without disturbing the alignment of the pellets nor their structural integrity. Once the device is removed, the incision can be closed with surgical glue or other known closure methods.
U.S. Pat. No. 3,402,712 discloses a gravity-feed pellet implanter has a tooth-engaging notch on the side of its plunger rod near its distal end, and a toothed cam extending into the plunger-containing bore and spring-biased against the notched side of the plunger; the toothed cam prevents advance of the plunger unless a pellet is in transport and prevents movement of pellets toward the needle unless the plunger is being advanced.
U.S. Pat. No. 4,154,239 discloses an implanter by which pelleted drugs can be inserted or implanted under the skin of an animal typically to promote fattening of beef cattle and the like. The device includes a thrust pin which can be pushed through a tube containing the pellets to eject them into and through a hollow needle at the front of the device. A mechanism acts on the pin to push it in the forward direction and a return spring acts to return it to its rest position.
U.S. Pat. No. 5,147,295 discloses an implanting gun apparatus. A drive rod is linearly moveable in a handle assembly by a first pivotable linkage actuated by a trigger, to urge a pellet from a carrier through a head assembly and into a needle. A second pivotable linkage, also actuated by the trigger, retracts the needle, the head assembly, and the carrier into the handle after the pellet has been urged into the needle. The gun apparatus is particularly adapted to implant pellets in animals, particularly as medicament pellets.
U.S. Pat. No. 7,850,639 discloses a device for inserting implantable objects beneath the skin of a patient includes a handle for grasping the device and a base connected to the handle. The base comprises a post, a cannula, and a flexible actuator positioned in an angled track. The cannula is positioned coaxially around and is longitudinally slidable over the post from an extended position, where an implantable object is retained in the cannula, to a retracted position, where the implantable object is released from the cannula. A flexible actuator positioned on an angled track in the base is slidably engaged with a boss on the cannula and is used to move the cannula from an extended position to a retracted position to release the implantable object from the cannula; the actuator flexes between a locked and an unlocked position. The angled track provides for control of the release of the implantable object.
The present invention provides numerous advantages over known devices. The instant invention includes devices, tools, and kits for improving the ease, consistency, sterility, and delivery of subcutaneous medicaments, such as hormone pellets, while reducing the risk of complications from contamination, the risk of injury to the operator, and the frequency of treatments required.